Technical Field
The present invention relates to a wiring substrate and a semiconductor package.
Related Art
There is known a wiring substrate in which a through-hole is provided in a core substrate, and a ceramic substrate is buried within the through-hole. In this wiring substrate, a build-up layer in which a wiring layer and an insulating layer are alternately provided can be formed on the upper and lower surfaces of the core substrate and the ceramic substrate, and a semiconductor chip can be mounted on the uppermost wiring layer. In the ceramic substrate, plural through-wirings are formed, and the wiring layer on the upper surface side and the wiring layer on the lower surface side are connected to each other via the through-wiring.    [Patent Document 1] Japanese Patent Application Publication No. 2012-74536A
However, it is difficult to realize pitch-narrowing of the through-wiring formed in the ceramic substrate. In addition, assuming that the pitch-narrowing could be realized, it would be needed to achieve position adjustment with high precision on the occasion of disposing the ceramic substrate in the through-hole of the core substrate.